Casting apparatus



Oct. 28, 1958 v R. w. WIIINTE'RS 2,857,637

' CASTING APPARATUS Filed May 31, 1955 I 2 Sheets-Sheet 1 FIG. l'

7 Filed May 31, 1955 Oct. 28, 1958 R w, wlNTERS 2,857,637

CASTING APPARATUS 2 Sheets-Sheet 2 FIG.2

/4 I I $2 n 8 4 5 2?;iI(Ill/113717511111!IIIIlIIIIIIlIIi/I4 H 'I//// W4l2 44w A 1 l3 III/ I'IIIIIIIIiI/IIII07171111111111111114 INVENTOR.ROBERT W. WINTERS 2 ATTORNEYS 'CASTIN G APPARATUS Robert W. Winters,Branforil, 'Conn., assignor to Olin 'Mathieson Chemical Corporation,East Alton, 111., a corporation of Virginia Application MaySl, 1955,Serial No. 512,192

8 Claims. (Cl. 2257.4)

This invention'relates to the casting :of metal and more specifically toan improved mold structure especially adapted for the continuous castingof metal.

One known method'of continuous casting of metal ina shape having a widthfar in excessof the thickness of the casting involves pouring andsolidification of the molten metal between two broad moving metal belts.In aption has resulted largely because of the frictional resistancepresented by this type of side wall to the metal being shaped. Toovercome this problem moving side walls of various types includinglaminated walls have also been tried; but penetration by the moltenmetal and undesired welding between the side belts and the metal beingcast have prevented the successful adoption ofsuch structures and anyworthwhile realization of the potential advantages of endless beltcasting machines. -;prior: types of side wall structures have been.furtherchar- Most of these acterized by inability to adjust tovariation in belt spacing and by disadvantageous heat conductivity forthe successful casting of metal in the shape of a thin slab or strip.Specifically a disadvantage of these priorart .moldside walls has beenthe difficulty of obtaining an operable fit at the edges of the broadmoving casting belts adjacent the side walls and especially the type offit necessary to prevent the escape of molten metal between the belt andside wall and to avoid the resultant inferiorperformance wheneverexcessive flash, for example, is formed by the escaping metal.

Therefore one object of this invention is to overcome the aforementioneddifficulties by provision of a mold .side wall of a novel construction.Another object is to provide an improved moving belt type of continuouscasting apparatus especially suitable for the production of metal stripand the like. A still further object is to provide a novel laminated butsturdy side wall structure suitable for the casting of relatively highmelting ,point or refractory metals and alloys. Other objects andadvantages of this invention will be apparent from the follow- .ingdescription and the accompanying drawing in which:

Figure 1 is a semi-diagrammatic elevational view showing a typicalmoving belt type of continuous casting machine having side walls inaccordance with this invention;

Figure 2 is a cross-sectional view taken on line II.II of Figure l; and

Figure 3 is a perspective view of a part of a preferred embodiment ofthe side wall of this invention with an end shown in cross section.

Inaccordance with this invention there is provided a relativelycompressible mold wall or a continuous casting edge dam made up of abundle of refractory strands or wires and more specifically of strandsof metal such as steel or the like. The flexibility and thecompressibility States Patent regularities. I a cable so as to extendstraight along the length of the 'o'f the mold wall accomplish animproved seal with the adjacent mold faces which in operation havesurface i'r- The strands may be laid down together as cable or maybetwisted as they are put together to form a twisted strand cable. To formthe side wall or edge 'dam of a continuous casting mold, it is preferredthat the strands of the cable or wire rope be convolutedly woundtogether to form an endless belt or cable. It is further preferred thatthe strands be so assembled as to lustrated but not limited by areference to the rather diagrammatic representation of Figures 1 and 2of a continuous casting machine in which 1 and 2 each refers'to anendless side wall or edge dam belt of this invention which is adapted'tobe sandwiched in operative position between endless broad metal moldface belts or bands 3 and 4 at the lateral edges of the face belts toform therewith a casting region or cavity. Side walls 1 and -2 arecarried along on and adjacent the lateral edges of belt 3, which in turnis supported on and passes around end rolls 5 and 6. The other maincasting or mold face belt 4, which like belt 3 is made of a strip ofsuitable metal such'as stainless steel, is carried over another pair ofend rolls 7 and 8. As shown in Figure 2, belt 4 overlies belt 3 and inthe casting area or region of the machine belts 3 and 4 pass in closelyspaced parallel relationship. Side wall belt 1is carried about belt 3 atone side of the rolls :5 and 6 while side wall belt 2 is carried at theother side of rolls 5 and 6 about belt 3. In this casting area, thelower mold face belt 3 is backed up by a series of rolls 9 and uppermold face'belt 4 is in turn backed up by a series of rolls 10. Asassembled in operative relationship in the casting area of the machine,side belt 1 forms the edge dam 11 and belt 2 forms the edge dam 12 ofthe casting cavity 13 of rectangular cross section defined by the moldface belts 3 and 4 and the edge dams 11 and 12. At the casting cavity 13the lateral edges of face belts 3 and 4 are pressed at intervals againstthe edge dams 11 and 12 by any suitable instrumentalities such as theseries of support rolls 9 and 10 the ends of which are'forced againstthe back side of the lateral edges of the face belts 3 and 4 so as tosqueeze belts 3 and 4 against the compressible'edge dams 11 and 12,which are backed up by guide bars 14 and 15, respectively. Side belts 1and 2 and face belts 3 and 4 are driven by any suitable mechanism tomove with the casting 18 as it forms in andtraverses the mold cavity 13.

In operation molten metal from a reservoir or crucible 16 is supplied tothe tundish 17 which feeds a stream "of metal at a desirable flow rateinto the cavity 13 in which solidification of the metal occurs toproduce the relatively broad thin slab 18. To aid in solidifying themetal, the faces of belts 3 and 4 exterior to cavity 13 may be subjectedto a stream of coolant.

The side wall or continuous casting edge dam structure of thisinvention, as illustrated in greater detail in Figure 3, is formed of aplurality of metallic strands or wire which are wound and twisted toproduce an endless cable 19 or loop having a length such as to permitthe cable to pass between the main or mold face belts 3 -and-4 of thecasting machine hereinbefore described and to also pass over and extendbetween the end rolls of the machine on the return side of those rolls.A sufficient number of the metallic strands are laid together or pliedup so as to form a cable of a cross section large enough to fill thelateral edge portions of the gap between the parallel spaced mold faceparts 3 and 4 at the casting cavity or chamber 13, Figure 2. In thespecific embodiment illustrated in Figure 3, the edge dam structure 19consists of a composite cable composed of six smaller cables 20 each ofwhich in turn consist of 19 twisted steel wires 21. It will beunderstood that a greater or lesser number of component cables may beused and that a greater or lesser number of strands of either uniform ordifferent sizes may form each com ponent cable. At least part of thestrands are of rounded or of such polygonal cross-sectional shape aswill permit a degree of mobility to the metallic strands and alsocontribute to compressibility of the structure. Preferably the componentmembers of the edge dam cable are assembled or formed in such a mannerso as to make a cable or side wall 19 of at least an approximatelyquadrangular shape as shown. When installed in the casting apparatus,one of the surfaces 22 of the endless side wall belt 19, afterapplication of a suitable mold dressing is presented to the metal beingcast in cavity 13, Figure 2.

The endless side wall or edge dam structure formed in this manner ofstrands of steel provides a laminated mold wall characterized by highflexibility, almost any desired degree of compressibility as determinedby numher and type of strands and their manner of assembly, highrefractoriness and by suitable heat conductivity which is adaptable tomodification by the application of mold dressing or coating compound atleast to the surface of the cable which is to be exposed to the moltenmetal undergoing casting. The flexible, compressible mold wall structureof this invention is especially adaptable to carrying a mold dressingbecause of the presence of interstices between the steel strands whichconstitute the cable. The mold structure provided is capable of carryingalmost any type of mold dressing material which is needed to facilitatethe parting of the casting metal from the mold wall and to preventwelding or mechanically interlocking the metal casting and the mold sidewall. Any suitable refractory parting or mold dressing compound can beapplied such as graphite in a suitable vehicle, or a silicone, silcagel, graphite compound or the like. A suitable silicone isdimethylpolysiloxane.

By means of this invention there is provided a sturdy mold side wall orcontinuous casting edge dam structure of metal which is sutficientlycompressible to enable it to adapt itself when under proper clampingpressure to the desired spacing between mold face plates or face platebelts of a casting apparatus and especially of a continuous castingmachine where a continuous and positive seal is made with the faceplates or belts. The side wall is adapted to carry any suitable molddressing applied to it. Furthermore, the multistrand mold wall iscapable of withstanding the temperatures encountered in the casting ofmost metals including the more refractory metals and alloys withoutdistorting or developing fractures and without loss of the continuousand positive seal.

While the invention has outstanding utility in the art of continuouscasting with respect to which it has been described herein, it will beunderstood that it has utility with any metal casting apparatus such asthe permanent metallic type of two-part book mold.

Since many other embodiments may occur to those skilled in the art, itis to be understood that the foregoing is intended by way ofillustration and not as a limitation of the scope of the presentinvention except as set forth in the appended claims. I

What is claimed is:

1. In apparatus for continuously casting wide thin shapes such as stripfrom molten metal, a pair of endless elongated moving broad metal bandsat least a portion of each of which is traveling in the same directionin spaced face-toface relationship and a mold side wall belt ofrectangular cross sectional contour moving with and clamped between saidbands at each of the opposing lateral edge portions of said bands, eachof said side wall belts comprising an endless wound multi-strand twistedsteel cable compressible in the direction of its thickness and defininga rectangular casting cavity together with said bands, said strands ofsaid cable being contiguous and of substantially polygonal crosssectional shape having limited mobility with respect to each other andhaving interstitial spaces therebetween for reception of a mold dressingmedium and a mold dressing medium being received in said spaces andcoating at least the outer layer of strands facing said cavity.

2. In apparatus for the casting of metals, a molten metal pressureretaining mold wall comprising a transversely compressible bundleconsisting essentially of wound metallic strands each stacked up so asto be substantially continuously contiguous with neighboring strandsadjacent to each other both in the direction of mold wall width andthickness and running continuously in the longitudinal direction in saidmold wall and at least part of said strands being of such substantiallyrounded cross sectional configuration and thinness permitting a degreeof transverse mobility with respect to each other under the forces ofsaid compression and the pressure of said molten metal, said bundleconsisting of a plurality of rows and layers of said strands havinginterstitial spaces therebetween adapted for reception of a molddressing medium said bundle including an outer layer of strands at leasta part of which is adapted to form at least a side wall part facing saidmolten metal.

3. In an apparatus for the casting of metals, the combination of a pairof solid mold face plate members disposed in spaced apart face-to-facerelationship and at each of the opposed lateral edge portions thereof atleast one mold side wall member clamped between said opposing edgeportions and each comprising a longitudinally extending bundleconsisting of metallic strands at least a substantial part of which areso shaped cross sectionally as to render substantially all of themrelatively mobile transversely with respect to the length of saidbundle, said strands being wound in a row and columnar arrangement withrespect to the width and height of said bundle measuring in a transversedirection, each of said strands being contiguous with adjacent strandssubstantially completely along the length thereof, said bundle havinginterstitial spaces between the strands and a mold dressing mediumreceived in said spaces and coating at least the outer layer of strandsfacing said molten metal, said face plate and side wall members togetherdefining a substantially rectangular casting cavity for retention ofsaid molten metal.

4. The apparatus of claim 3 wherein said side wall member is a metalcable consisting of a relatively large number of twisted refractorystrands each in linear contiguity with an adjacent strand and of a roundcross sectional shape and size facilitating limited transverse mobilityand compressibility.

5. The apparatus of claim 3 wherein said side wall member is acompressible bundle of quadrilateral cross sectional contour.

6. The apparatus of claim 3 wherein the strands consist of refractorymetal and wherein the dressing is a refractory compound.

7. Apparatus for continuously casting wide thin shapes such as stripfrom molten metal comprising a pair of endless elongated moving broadmetal bands at least a portion of each of which is traveling in the samedirection in spaced face-to-face relationship and a mold side wall beltmoving in unison with and clamped between each of the opposing lateraledge portions of said bands, said side wall belt comprising an endlessconvolutely wound multi-strand metal cable, the individual strands ofwhich run continuously in the direction of belt length and are stackedup in a transversely compressible bundle so as to be substantiallycontinuously contiguous with adjacent neighboring strands in thedirections of belt width and thickness, said strands being of suchsubstantially rounded cross sectional configuration and thinness as tohave interstitial spaces therebetween and to permit a degree oftransverse mobility with respect to each other for obtainment of saidtransverse compressibility under the forces of transverse compressionbetween said edge portions and the outward force of said molten metal,said bundle having at least a partially compressed thicknecess betweensaid lateral edge portions not less than that of the edge portionspacing.

8. In an apparatus for the casting of metals, the combination of a pairof solid mold face plate members disposed in spaced apart face-to-facerelationship and at each of the opposed lateral edge portions thereof atleast one mold side wall member clamped between said opposing edgeportions and each comprising a longitudinally extending bundleconsisting of metallic strands relatively mobile transversely withrespect to the length of said bundle, said strands being arrayed in arow and columnar arrangement with respect to the width and height ofsaid bundle measuring in a transverse direction, each of said strandsbeing contiguous with adjacent strands substantially completely alongthe length thereof, said bundle having interstitial spaces between thestrands and a mold dressing medium received in said spaces and coatingat least the outer layer of strands facing said molten metal, said faceplate and side wall members together defining a substantiallyrectangular casting cavity for retention of said molten metal, said moldside wall comprising a flexible cable of rectangular cross sectionalcontour formed of a plurality of twisted strands of refractory metal.

References Cited in the file of this patent UNITED STATES PATENTS2,285,740 Merle June 9, 1942 2,554,356 Beare May 22, 1951 2,640,235Hazelett June 2, 1953 2,668,987 Harris et a1. Feb. 16, 1954 FOREIGNPATENTS 383,313 Italy Oct. 2, 1940

